Diesel combustion control with digital rate shaping
Ladda ner
Typ
Examensarbete för masterexamen
Master's Thesis
Master's Thesis
Program
Automotive engineering (MPAUT), MSc
Publicerad
2023
Författare
Kumar, Sachit
Yalmuri Krishnamurthy, Akshay
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
Due to the impact of the transport industry on the environment, stringent emission
norms are being pushed for implementation. The real challenges for OEM’s are to keep
up with the regulations. The transition to complete electric future is still distant, and the
existing diesel engines must survive for at least 5-10 years. Therefore, OEM’s must
achieve the legislative requirements with fuel consumption benefits using the available
technology. One of the techniques available is diesel combustion control with digital
rate shaping. Therefore, the thesis will investigate this method with triple pilot injection
strategy and study the improvements in terms of fuel efficiency and emissions.
The work is carried out in two different parts; first, the Injector capabilities were tested
in FIE (Fuel Injection Equipment) test rig at different load points with shorter and
longer dwell times for different fuel quantities at different rail pressures. The aim was
to investigate for injector performance in terms of minimum possible dwell time, fuel
quantity, repeatability, and robustness of the injector. Resultsshow inconsistent injector
performance.
Second, the combustion is studied in a single-cylinder test rig. The test was investigated
for one specific load point. The Injector capabilities and boundary conditions for triple
pilot injection were again tested. Based on the Rate of heat release curve, each
parameter, i.e. dwell time, fuel quantities and rail pressures were manually varied. Next,
design of experiments (DoE) was set up using ETAS ASCMO. Running the DoE point
in single-cylinder test rig, a combustion model was created from this data. Dwell time,
fuel quantities and rail pressure as input parameters different response curves were
created to see effects of these parameters on emissions, bsfc and combustion noise.
These curves are then used to define a calibration strategy. Optimisations performed in
the software are verified in the single-cylinder test rig.
The optimised injection strategy was validated in Gen IV Volvo multi-cylinder
production engine. The results replicate the inconsistent performance of injector seen
in FIE test rig and do not justify the supplier claim. However, based on the trend a
description about how to efficiently balance the calibration to achieve lowest engine out emissions, combustion noise and achieve efficiency through model-based
calibration is proposed.
Beskrivning
Ämne/nyckelord
Triple pilot injection , Digital rate shaping , Injection strategy , Engine calibration , Model-based calibration , FIE